Optimal Selection of Number and Location of Meteo-Hydrological Monitoring Networks on Vu Gia – Thu Bon River Basin using GIS

Meteorological data play a particularly important role in hydrologic research because the climate and weather of an area exert a profound influence on most hydrologic processes. Meanwhile, hydrological data are critical for performing a range of purposes, including water resources assessment, impacts of climate change and flood forecasting and warning. It can be said that the prevention of disasters caused by floods and droughts would be impossible without rational forecasting technology based on an understanding of the rainfall-runoff phenomenon and statistical analysis of past hydrological data, which cannot be achieved without meteo-hydrological observations. The lack of adequate meteo-hydrological data affects the ability to model, predict and plan for catastrophic events such as floods and droughts which have obvious negative impacts on public health and socio-economic aspects. The accurate estimation of the spatial distribution of meteorological and hydrological parameters requires a dense network of instruments, which entails large installation and operational costs. It is thus necessary to optimize the number and location of meteo-hydrological stations. This paper presents a GIS-based approach to establishing an optimal meteo-hydrological station network on Vu Gia- Thu Bon river basin for developing an up-to-date real time flood warning system. Based on statistical analysis of the annual rainfall total data at 9 existing gauges in the study area from 1980 to 2013, it showed that the error of the existing network was about 7.47%. Considering 9 rain gauges as a standard representative of rainfall over the region, if the error decreases from 7.47% to 5%, the number of additional rain gauges should be 20. For adequate and economical network design, these additional rain gauges were spatially distributed between the different isohyetals after considering the relative distances between rain gauges, their accessibility, personnel required for making observations using multi-layers analysis and spatial interpolation. For hydrological stations, based on consideration existing network with the requirements set out by the flood warning system, the number of stations should be five. In terms of spatial distribution, three stations were distributed across two main tributaries of Vu Gia- Thu Bon river basin, behind the dams for water discharge calibration and the others were located on downstream for water stage calibration. The results of the study provided a scientific approach can be applied to optimizing the meteo-hydrological station network over the river basin

Health insurance reform in Vietnam: a review of recent developments and future challenges

Vietnam is undertaking health financing reform with a view to achieve universal coverage of health insurance within the coming years. To date, around half of the population is covered with some type of health insurance or prepayment. This review applies a conceptual framework of health financing to provide a coherent assessment of the reforms to date with respect to a set of key policy objectives of health financing, including financial sustainability, efficiency in service provision, and equity in health financing. Based on the assessment, the review discusses the main implications of the reforms focusing on achievements and remaining challenges, the nature of the Vietnamese reforms in an international perspective, and the role of the government. The main lessons from the Vietnamese experiences, from which other reforming countries may draw, are the need for sustained resource mobilization, comprehensive reform involving all functions of the health financing system, and to adopt a long-term view of health insurance reform. Future analysis should include continued evaluation of the reforms in terms of impacts on key outcomes and the political dimensions of health refor

The Improvement Model of Navigational Safety for Inland Waterway Transport

This paper aims at evaluating navigational safety for inland waterway transport (IWT). In doing so, the literature and operational features of IWT were initially reviewed to figure out risk elements (REs) influencing the navigational safety for IWT. After that, a fuzzy Analytic Hierarchical Process (AHP) approach was adopted to estimate the weight for the likelihood and consequence measures of REs. Then, continuous risk matrix (RM) was introduced to identify REs\u27 risk level. Lastly, to test the proposed research model\u27s applicability, IWT operators across Vietnam were empirically surveyed. The empirical findings could be useful for IWT operators in launching managerial policies to boost their navigational safety. Furthermore, the proposed risk evaluation framework may serve as a methodological reference in relevant literature

Synthesis of bio-polyols by epoxide ring opening reaction with H2O as a reagent

The different nucleophilic reagents have been using in epoxide ring opening reactions among which water is the most preferable. At first, the epoxide group must be protonated by water in the presence of H2SO4 as catalyst. The successful epoxide ring opening reaction of epoxidized soybean oil (ESO) by water in the H2SO4 environment was verified by FTIR and H-NMR spectroscopy. The effect of reaction parameters like the amount of reagents, catalyst, temperature and time of a polyol synthesis were studied through the hydroxyl and oxirane oxygen content of product. Moreover, the impact of the parameters on the correlation P/E was determined by comparing a hydroxyl group formation to an epoxide group consumption. When the hydroxylation reaction was carried out with ESO:H2O mole ratio of 1:15; in 8 wt.% H2SO4; at temperature of 70 oC and in 5 hours, the hydroxyl content of 358.51 mgKOH/g of the obtained product was achieved. Keywords. Epoxidized vegetable oil, biopolyol, epoxide ring-opening, epoxidized soybean oil

The Improvement Model of Navigational Safety for Inland Waterway Transport

This paper aims at evaluating navigational safety for inland waterway transport (IWT). In doing so, the literature and operational features of IWT were initially reviewed to figure out risk elements (REs) influencing the navigational safety for IWT. After that, a fuzzy Analytic Hierarchical Process (AHP) approach was adopted to estimate the weight for the likelihood and consequence measures of REs. Then, continuous risk matrix (RM) was introduced to identify REs\u27 risk level. Lastly, to test the proposed research model\u27s applicability, IWT operators across Vietnam were empirically surveyed. The empirical findings could be useful for IWT operators in launching managerial policies to boost their navigational safety. Furthermore, the proposed risk evaluation framework may serve as a methodological reference in relevant literature

Allogeneic human umbilical cord-derived mesenchymal stem/stromal cells for chronic obstructive pulmonary disease (COPD): study protocol for a matched case–control, phase I/II trial

Introduction The global prevalence of chronic obstructive pulmonary disease (COPD) is increasing, and it has become a major public health burden worldwide, including in Vietnam. A large body of preclinical and clinical studies supports the safety of mesenchymal stem/stromal cells (MSCs) in the treatment of lung injury, including COPD. The aim of this trial is to investigate the safety and potential therapeutic efficacy of allogeneic administration of umbilical cord-derived MSCs (UC-MSCs) as a supplementary intervention in combination with standard COPD medication treatments in patients with moderate-to-severe COPD based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2019 and Vietnam Ministry of Health's guidelines. Methods and analysis This matched case-control phase I/II trial is conducted at Vinmec Times City International Hospital, Hanoi, Vietnam between June 2020 and December 2021. In this study, 40 patients will be enrolled and assigned into two age-matched, gender-matched and COPD condition-matched groups, including a UC-MSC group and a control group. Both groups will receive standard COPD medication treatment based on the GOLD 2019 guidelines and the Vietnam Ministry of Health protocol. The UC-MSC group will receive two doses of thawed UC-MSC product with an intervention interval of 3 months. The primary outcome measures will include the incidence of prespecified administration-associated adverse events and serious adverse events. The efficacy will be evaluated based on the absolute changes in the number of admissions, arterial blood gas analysis, lung function and lung fibrosis via CT scan and chest X-ray. The clinical evaluation will be conducted at baseline and 3, 6 and 12 months postintervention. Ethics and dissemination Ethical approval was secured from the Ethical Committee of Vinmec International Hospital (number:166/2019/Q -VMEC) and Vietnam Ministry of Health (number:2002/Q -BYT). The results will be reported to trial collaborators, publication in peer-reviewed academic journals. Trial registration number NCT04433104

A Study Of UV-curable Offset Ink Emulsified With An Alternative Isopropyl Alcohol-free Fountain Solution

In the present research, fountain solution without isopropyl alcohol (IPA) for Ultraviolet offset curing ink (UV ink) was prepared by using Ethylene Glycol Mono-butyl Ether (EGME) as a substitute for IPA. The effect of EGME concentration on the water pick-up characteristics, tack value, rheological behaviors, and curing time of UV offset inks was investigated. Water pick-up characteristics, tack value and rheological behaviors were measured by Duke Ink water emulsification tester, Tack-o-scope and cone-plate rheometer, respectively. The curing time of the UV ink was evaluated by the rub test of printed sheet samples proofed on the polymer film at the standard solid ink density and the same ink thickness. The results revealed that an increase in EGME concentration increased the water pick-up characteristics of the UV ink. There was no significant influence of EGME on the tack value of UV inks. However, the tack value of UV ink was significantly affected by fountain concentration in UV inks and UV ink color. The addition of EGME reduced the dynamic viscosity and thixotropic property of UV inks but did not change the flow behavior of UV ink as shear thinning. This study indicates that UV ink emulsified with a higher EGME concentration fountain solution needs a longer curing time. The cyan UV ink has the longest curing time. Finally, the fountain solution of 10% EGME exhibited good performance in water pick-up characteristics, tack value, rheological behaviors, and curing time of UV inks

Chênh lệch tiền lương tại Đồng bằng sông Cửu Long dưới góc độ tiếp cận về giới tính và khu vực thành thị - nông thôn

This study analyzes the wage differential of male and female workers, and labor in urban and rural areas in the Mekong Delta provinces using the VHLSS 2014 data. The results of the decomposition of the wage disparity between men and women show unexplained difference has the major contribution in the wage gap between men and women, in particular the differences in the returns to academic and professional degrees for male and female workers. Meanwhile, the explained difference has lower explanatory power, suggesting that most of attributes of male and female labor do not significantly differ. The results of the decomposition of urban-rural wage differential show the opposite: the difference is mainly due to the fact that urban workers are more educated than rural labor, while the unexplained difference has lower explanatory power. Based on these results, the paper proposes a number of recommendations to reduce the income gap in the Mekong Delta

Facile Synthesis of Carbon Quantum Dots by Plasma-liquid Interaction Method

Carbon quantum dots (CQDs) are a novel type of fluorescent nano-materials with various unique properties. They are recently attracting enormous interest due to their superiority in water solubility, chemical inertness, low toxicity, ease of functionalization as well as resistance to photo-bleaching and potential applications in biomedical indication, photo-catalysis, energy conversion, optoelectronics, and sensing. In this work, we present a facile and environmentally friendly synthesis of CQDs based on plasma - liquid interaction method. This is a single-step method and does not use toxic chemicals. The size distribution of obtained CQDs is rather uniform at approximately 3 nm. The emission peak of CQDs shifts from 427 nm to 523 nm as the excitation wavelength is varied from 340 nm to 460 nm. The non-equilibrium reactive chemistry of plasma liquid interaction is responsible for acceleration of the CQDs formation process